diff -r 000000000000 -r 6474c204b198 b2g/components/WebappsUpdateTimer.js
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/b2g/components/WebappsUpdateTimer.js	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,67 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this file,
+ * You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+/**
+ * This component triggers an app update check even when system updates are
+ * disabled to make sure we always check for app updates.
+ */
+
+"use strict";
+
+const Cc = Components.classes;
+const Ci = Components.interfaces;
+const Cu = Components.utils;
+
+Cu.import("resource://gre/modules/XPCOMUtils.jsm");
+Cu.import("resource://gre/modules/Services.jsm");
+Cu.import("resource://gre/modules/WebappsUpdater.jsm");
+
+function debug(aStr) {
+  //dump("--*-- WebappsUpdateTimer: " + aStr);
+}
+
+function WebappsUpdateTimer() {
+}
+
+WebappsUpdateTimer.prototype = {
+  QueryInterface: XPCOMUtils.generateQI([Ci.nsITimerCallback]),
+  classID: Components.ID("{637b0f77-2429-49a0-915f-abf5d0db8b9a}"),
+
+  notify: function(aTimer) {
+    try {
+      // We want to check app updates if system updates are disabled or
+      // if they update frecency is not daily.
+      if (Services.prefs.getBoolPref("app.update.enabled") === true &&
+          Services.prefs.getIntPref("app.update.interval") === 86400) {
+        return;
+      }
+    } catch(e) {
+      // That should never happen..
+    }
+
+    // If we are offline, wait to be online to start the update check.
+    if (Services.io.offline) {
+      debug("Network is offline. Setting up an offline status observer.");
+      Services.obs.addObserver(this, "network:offline-status-changed", false);
+      return;
+    }
+
+    // This will trigger app updates in b2g/components/WebappsUpdater.jsm
+    // that also takes care of notifying gaia.
+    WebappsUpdater.updateApps();
+  },
+
+  observe: function(aSubject, aTopic, aData) {
+    if (aTopic !== "network:offline-status-changed" ||
+        aData !== "online") {
+      return;
+    }
+
+    debug("Network is online. Checking updates.");
+    Services.obs.removeObserver(this, "network:offline-status-changed");
+    WebappsUpdater.updateApps();
+  }
+};
+
+this.NSGetFactory = XPCOMUtils.generateNSGetFactory([WebappsUpdateTimer]);